Iray rendering - denoiser now effective?

See that warning, how can I make the denoising to work with my Ryzen9 ?
Not possible yet?

Then how about the hairlights I have made with dome+texture and a large rect light behind her, see they look so good on Path Traced:

Why is that light missing totally on Iray? Otherwise the Iray looks great!!

I also get the Denoiser not available message on my i9. Sometimes, a message out of memory. RTX3080 when running Iray.


Hello @pekka.varis & @fsheng21! I have alerted the development team about this post.

pekka.varis, it looks like you are falling back on CPU mode in which case the denoiser is not available, it is CUDA (GPU) only.

fsheng21, this also sounds like the GPU runs out of memory and falls back to CPU which unfortunately means the denoiser is unavailable.

ok, thanks! Why am I alling back on CPU mode?
I have here RTX 2070 Super & Ryzen 9 3900X

I was running a small scene to the retro contest. RTX3080 & I9-10900K.
and with three light source.

My guess would be that you run out of GPU memory, but hard to tell without more information. Does the denoiser work for a trivial scene?

The latest Create & CC connector is still having problems with Iray photoreal on hair key light.

Path traced:


Which version of Create are you using? It looks to me that the hair is black in Iray, so I assume there is some issue with the hair material, or even parts of the hair geometry that is missing.

Even with latest Create 2016.3.6.
the same problem exists:

With Path Traced it looks ok:

I guess it is the fact that Omniverse CC connector does not support iray.
So you want me to send you the CC project so you can try this yourself?


The connector shouldn’t have to support Iray specifically, but could of course trigger some case that is not yet supported in Iray or buggy. Could you provide the usd scene (including all the materials and textures, etx) that shows this issue in create?

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Sure, tomorrow :) thanks!

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Hi Pekka, after speaking with the devs it sounds like this scene is probably applying a hair shader on triangle data instead of hair geometry (curves). This is not really correct and for that reason not supported by Iray, though we might consider adding some kind of support for this similar to what RTX Path-Traced does. If this is the case the hair would render completely black, which seems consistent with your images.

It would help a lot if you could provide the USD scene. Then we can verify that this is indeed the issue and would also help us judge if we could do something for this specific case.


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Yes, PM sent to you!

This scene actually worked fine for me, so guess it doesn’t use a hair shader that requires curves in Iray. But I don’t understand why it doesn’t work for you… I also tried with 2021.3.6.

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Same here now it works!

But when I try to render out some seq, it only renders with
Path Trace samples per pixel: 1.
If I try 2 or something else i get no render frames saved, it just renders forever the first frame:

I raised the iray / Scheduler Settings / Samples per frame to 50 and I got that pretty iray render attached above.

But that setting does not reflect to output sequence renders, they look like this: ( with the only setting that works when rendering a seq: Path Trace samples per pixel: 1.)

What could be the solution?

Hmm, tried this and upping the path trace samples per pixel option in the Movie Capture tool works fine for me. I can render the sequence and am getting the expected quality. No idea why that wouldn’t work for you.

Unfortunately the movie tool will limit Iray to the number of samples that is set in the capture settings while capturing, so in this case Iray will stop rendering as soon as it hits 1 spp no matter what the samples per frame option is set to.

Do you see anything suspicious in the log?

Thank you. It shall take few days until I can focus on this case again…

Do you mean capturing the motion or…?

Yeah, while the Movie Capture tool is rendering the animation.

Then I feel Iray is better for stills, until this is developed further.
I am fine with path-traced :)